// SPDX-License-Identifier: GPL-2.0 /* * cfg80211 scan result handling * * Copyright 2008 Johannes Berg * Copyright 2013-2014 Intel Mobile Communications GmbH * Copyright 2016 Intel Deutschland GmbH * Copyright (C) 2018-2019 Intel Corporation */ #include #include #include #include #include #include #include #include #include #include #include #include "core.h" #include "nl80211.h" #include "wext-compat.h" #include "rdev-ops.h" /** * DOC: BSS tree/list structure * * At the top level, the BSS list is kept in both a list in each * registered device (@bss_list) as well as an RB-tree for faster * lookup. In the RB-tree, entries can be looked up using their * channel, MESHID, MESHCONF (for MBSSes) or channel, BSSID, SSID * for other BSSes. * * Due to the possibility of hidden SSIDs, there's a second level * structure, the "hidden_list" and "hidden_beacon_bss" pointer. * The hidden_list connects all BSSes belonging to a single AP * that has a hidden SSID, and connects beacon and probe response * entries. For a probe response entry for a hidden SSID, the * hidden_beacon_bss pointer points to the BSS struct holding the * beacon's information. * * Reference counting is done for all these references except for * the hidden_list, so that a beacon BSS struct that is otherwise * not referenced has one reference for being on the bss_list and * one for each probe response entry that points to it using the * hidden_beacon_bss pointer. When a BSS struct that has such a * pointer is get/put, the refcount update is also propagated to * the referenced struct, this ensure that it cannot get removed * while somebody is using the probe response version. * * Note that the hidden_beacon_bss pointer never changes, due to * the reference counting. Therefore, no locking is needed for * it. * * Also note that the hidden_beacon_bss pointer is only relevant * if the driver uses something other than the IEs, e.g. private * data stored stored in the BSS struct, since the beacon IEs are * also linked into the probe response struct. */ /* * Limit the number of BSS entries stored in mac80211. Each one is * a bit over 4k at most, so this limits to roughly 4-5M of memory. * If somebody wants to really attack this though, they'd likely * use small beacons, and only one type of frame, limiting each of * the entries to a much smaller size (in order to generate more * entries in total, so overhead is bigger.) */ static int bss_entries_limit = 1000; module_param(bss_entries_limit, int, 0644); MODULE_PARM_DESC(bss_entries_limit, "limit to number of scan BSS entries (per wiphy, default 1000)"); #define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) static void bss_free(struct cfg80211_internal_bss *bss) { struct cfg80211_bss_ies *ies; if (WARN_ON(atomic_read(&bss->hold))) return; ies = (void *)rcu_access_pointer(bss->pub.beacon_ies); if (ies && !bss->pub.hidden_beacon_bss) kfree_rcu(ies, rcu_head); ies = (void *)rcu_access_pointer(bss->pub.proberesp_ies); if (ies) kfree_rcu(ies, rcu_head); /* * This happens when the module is removed, it doesn't * really matter any more save for completeness */ if (!list_empty(&bss->hidden_list)) list_del(&bss->hidden_list); kfree(bss); } static inline void bss_ref_get(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *bss) { lockdep_assert_held(&rdev->bss_lock); bss->refcount++; if (bss->pub.hidden_beacon_bss) { bss = container_of(bss->pub.hidden_beacon_bss, struct cfg80211_internal_bss, pub); bss->refcount++; } if (bss->pub.transmitted_bss) { bss = container_of(bss->pub.transmitted_bss, struct cfg80211_internal_bss, pub); bss->refcount++; } } static inline void bss_ref_put(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *bss) { lockdep_assert_held(&rdev->bss_lock); if (bss->pub.hidden_beacon_bss) { struct cfg80211_internal_bss *hbss; hbss = container_of(bss->pub.hidden_beacon_bss, struct cfg80211_internal_bss, pub); hbss->refcount--; if (hbss->refcount == 0) bss_free(hbss); } if (bss->pub.transmitted_bss) { struct cfg80211_internal_bss *tbss; tbss = container_of(bss->pub.transmitted_bss, struct cfg80211_internal_bss, pub); tbss->refcount--; if (tbss->refcount == 0) bss_free(tbss); } bss->refcount--; if (bss->refcount == 0) bss_free(bss); } static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *bss) { lockdep_assert_held(&rdev->bss_lock); if (!list_empty(&bss->hidden_list)) { /* * don't remove the beacon entry if it has * probe responses associated with it */ if (!bss->pub.hidden_beacon_bss) return false; /* * if it's a probe response entry break its * link to the other entries in the group */ list_del_init(&bss->hidden_list); } list_del_init(&bss->list); list_del_init(&bss->pub.nontrans_list); rb_erase(&bss->rbn, &rdev->bss_tree); rdev->bss_entries--; WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list), "rdev bss entries[%d]/list[empty:%d] corruption\n", rdev->bss_entries, list_empty(&rdev->bss_list)); bss_ref_put(rdev, bss); return true; } static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, const u8 *subelement, size_t subie_len, u8 *new_ie, gfp_t gfp) { u8 *pos, *tmp; const u8 *tmp_old, *tmp_new; u8 *sub_copy; /* copy subelement as we need to change its content to * mark an ie after it is processed. */ sub_copy = kmalloc(subie_len, gfp); if (!sub_copy) return 0; memcpy(sub_copy, subelement, subie_len); pos = &new_ie[0]; /* set new ssid */ tmp_new = cfg80211_find_ie(WLAN_EID_SSID, sub_copy, subie_len); if (tmp_new) { memcpy(pos, tmp_new, tmp_new[1] + 2); pos += (tmp_new[1] + 2); } /* go through IEs in ie (skip SSID) and subelement, * merge them into new_ie */ tmp_old = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen); tmp_old = (tmp_old) ? tmp_old + tmp_old[1] + 2 : ie; while (tmp_old + 2 - ie <= ielen && tmp_old + tmp_old[1] + 2 - ie <= ielen) { if (tmp_old[0] == 0) { tmp_old++; continue; } tmp = (u8 *)cfg80211_find_ie(tmp_old[0], sub_copy, subie_len); if (!tmp) { /* ie in old ie but not in subelement */ if (tmp_old[0] != WLAN_EID_MULTIPLE_BSSID) { memcpy(pos, tmp_old, tmp_old[1] + 2); pos += tmp_old[1] + 2; } } else { /* ie in transmitting ie also in subelement, * copy from subelement and flag the ie in subelement * as copied (by setting eid field to 0xff). For * vendor ie, compare OUI + type + subType to * determine if they are the same ie. */ if (tmp_old[0] == WLAN_EID_VENDOR_SPECIFIC) { if (!memcmp(tmp_old + 2, tmp + 2, 5)) { /* same vendor ie, copy from * subelement */ memcpy(pos, tmp, tmp[1] + 2); pos += tmp[1] + 2; tmp[0] = 0xff; } else { memcpy(pos, tmp_old, tmp_old[1] + 2); pos += tmp_old[1] + 2; } } else { /* copy ie from subelement into new ie */ memcpy(pos, tmp, tmp[1] + 2); pos += tmp[1] + 2; tmp[0] = 0xff; } } if (tmp_old + tmp_old[1] + 2 - ie == ielen) break; tmp_old += tmp_old[1] + 2; } /* go through subelement again to check if there is any ie not * copied to new ie, skip ssid, capability, bssid-index ie */ tmp_new = sub_copy; while (tmp_new + 2 - sub_copy <= subie_len && tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) { if (!(tmp_new[0] == WLAN_EID_NON_TX_BSSID_CAP || tmp_new[0] == WLAN_EID_SSID || tmp_new[0] == WLAN_EID_MULTI_BSSID_IDX || tmp_new[0] == 0xff)) { memcpy(pos, tmp_new, tmp_new[1] + 2); pos += tmp_new[1] + 2; } if (tmp_new + tmp_new[1] + 2 - sub_copy == subie_len) break; tmp_new += tmp_new[1] + 2; } kfree(sub_copy); return pos - new_ie; } static bool is_bss(struct cfg80211_bss *a, const u8 *bssid, const u8 *ssid, size_t ssid_len) { const struct cfg80211_bss_ies *ies; const u8 *ssidie; if (bssid && !ether_addr_equal(a->bssid, bssid)) return false; if (!ssid) return true; ies = rcu_access_pointer(a->ies); if (!ies) return false; ssidie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); if (!ssidie) return false; if (ssidie[1] != ssid_len) return false; return memcmp(ssidie + 2, ssid, ssid_len) == 0; } static int cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss, struct cfg80211_bss *nontrans_bss) { const u8 *ssid; size_t ssid_len; struct cfg80211_bss *bss = NULL; rcu_read_lock(); ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID); if (!ssid) { rcu_read_unlock(); return -EINVAL; } ssid_len = ssid[1]; ssid = ssid + 2; rcu_read_unlock(); /* check if nontrans_bss is in the list */ list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) { if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) return 0; } /* add to the list */ list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list); return 0; } static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, unsigned long expire_time) { struct cfg80211_internal_bss *bss, *tmp; bool expired = false; lockdep_assert_held(&rdev->bss_lock); list_for_each_entry_safe(bss, tmp, &rdev->bss_list, list) { if (atomic_read(&bss->hold)) continue; if (!time_after(expire_time, bss->ts)) continue; if (__cfg80211_unlink_bss(rdev, bss)) expired = true; } if (expired) rdev->bss_generation++; } static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev) { struct cfg80211_internal_bss *bss, *oldest = NULL; bool ret; lockdep_assert_held(&rdev->bss_lock); list_for_each_entry(bss, &rdev->bss_list, list) { if (atomic_read(&bss->hold)) continue; if (!list_empty(&bss->hidden_list) && !bss->pub.hidden_beacon_bss) continue; if (oldest && time_before(oldest->ts, bss->ts)) continue; oldest = bss; } if (WARN_ON(!oldest)) return false; /* * The callers make sure to increase rdev->bss_generation if anything * gets removed (and a new entry added), so there's no need to also do * it here. */ ret = __cfg80211_unlink_bss(rdev, oldest); WARN_ON(!ret); return ret; } void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool send_message) { struct cfg80211_scan_request *request; struct wireless_dev *wdev; struct sk_buff *msg; #ifdef CONFIG_CFG80211_WEXT union iwreq_data wrqu; #endif ASSERT_RTNL(); if (rdev->scan_msg) { nl80211_send_scan_msg(rdev, rdev->scan_msg); rdev->scan_msg = NULL; return; } request = rdev->scan_req; if (!request) return; wdev = request->wdev; /* * This must be before sending the other events! * Otherwise, wpa_supplicant gets completely confused with * wext events. */ if (wdev->netdev) cfg80211_sme_scan_done(wdev->netdev); if (!request->info.aborted && request->flags & NL80211_SCAN_FLAG_FLUSH) { /* flush entries from previous scans */ spin_lock_bh(&rdev->bss_lock); __cfg80211_bss_expire(rdev, request->scan_start); spin_unlock_bh(&rdev->bss_lock); } msg = nl80211_build_scan_msg(rdev, wdev, request->info.aborted); #ifdef CONFIG_CFG80211_WEXT if (wdev->netdev && !request->info.aborted) { memset(&wrqu, 0, sizeof(wrqu)); wireless_send_event(wdev->netdev, SIOCGIWSCAN, &wrqu, NULL); } #endif if (wdev->netdev) dev_put(wdev->netdev); rdev->scan_req = NULL; kfree(request); if (!send_message) rdev->scan_msg = msg; else nl80211_send_scan_msg(rdev, msg); } void __cfg80211_scan_done(struct work_struct *wk) { struct cfg80211_registered_device *rdev; rdev = container_of(wk, struct cfg80211_registered_device, scan_done_wk); rtnl_lock(); ___cfg80211_scan_done(rdev, true); rtnl_unlock(); } void cfg80211_scan_done(struct cfg80211_scan_request *request, struct cfg80211_scan_info *info) { trace_cfg80211_scan_done(request, info); WARN_ON(request != wiphy_to_rdev(request->wiphy)->scan_req); request->info = *info; request->notified = true; queue_work(cfg80211_wq, &wiphy_to_rdev(request->wiphy)->scan_done_wk); } EXPORT_SYMBOL(cfg80211_scan_done); void cfg80211_add_sched_scan_req(struct cfg80211_registered_device *rdev, struct cfg80211_sched_scan_request *req) { ASSERT_RTNL(); list_add_rcu(&req->list, &rdev->sched_scan_req_list); } static void cfg80211_del_sched_scan_req(struct cfg80211_registered_device *rdev, struct cfg80211_sched_scan_request *req) { ASSERT_RTNL(); list_del_rcu(&req->list); kfree_rcu(req, rcu_head); } static struct cfg80211_sched_scan_request * cfg80211_find_sched_scan_req(struct cfg80211_registered_device *rdev, u64 reqid) { struct cfg80211_sched_scan_request *pos; WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held()); list_for_each_entry_rcu(pos, &rdev->sched_scan_req_list, list) { if (pos->reqid == reqid) return pos; } return NULL; } /* * Determines if a scheduled scan request can be handled. When a legacy * scheduled scan is running no other scheduled scan is allowed regardless * whether the request is for legacy or multi-support scan. When a multi-support * scheduled scan is running a request for legacy scan is not allowed. In this * case a request for multi-support scan can be handled if resources are * available, ie. struct wiphy::max_sched_scan_reqs limit is not yet reached. */ int cfg80211_sched_scan_req_possible(struct cfg80211_registered_device *rdev, bool want_multi) { struct cfg80211_sched_scan_request *pos; int i = 0; list_for_each_entry(pos, &rdev->sched_scan_req_list, list) { /* request id zero means legacy in progress */ if (!i && !pos->reqid) return -EINPROGRESS; i++; } if (i) { /* no legacy allowed when multi request(s) are active */ if (!want_multi) return -EINPROGRESS; /* resource limit reached */ if (i == rdev->wiphy.max_sched_scan_reqs) return -ENOSPC; } return 0; } void cfg80211_sched_scan_results_wk(struct work_struct *work) { struct cfg80211_registered_device *rdev; struct cfg80211_sched_scan_request *req, *tmp; rdev = container_of(work, struct cfg80211_registered_device, sched_scan_res_wk); rtnl_lock(); list_for_each_entry_safe(req, tmp, &rdev->sched_scan_req_list, list) { if (req->report_results) { req->report_results = false; if (req->flags & NL80211_SCAN_FLAG_FLUSH) { /* flush entries from previous scans */ spin_lock_bh(&rdev->bss_lock); __cfg80211_bss_expire(rdev, req->scan_start); spin_unlock_bh(&rdev->bss_lock); req->scan_start = jiffies; } nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_RESULTS); } } rtnl_unlock(); } void cfg80211_sched_scan_results(struct wiphy *wiphy, u64 reqid) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); struct cfg80211_sched_scan_request *request; trace_cfg80211_sched_scan_results(wiphy, reqid); /* ignore if we're not scanning */ rcu_read_lock(); request = cfg80211_find_sched_scan_req(rdev, reqid); if (request) { request->report_results = true; queue_work(cfg80211_wq, &rdev->sched_scan_res_wk); } rcu_read_unlock(); } EXPORT_SYMBOL(cfg80211_sched_scan_results); void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy, u64 reqid) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); ASSERT_RTNL(); trace_cfg80211_sched_scan_stopped(wiphy, reqid); __cfg80211_stop_sched_scan(rdev, reqid, true); } EXPORT_SYMBOL(cfg80211_sched_scan_stopped_rtnl); void cfg80211_sched_scan_stopped(struct wiphy *wiphy, u64 reqid) { rtnl_lock(); cfg80211_sched_scan_stopped_rtnl(wiphy, reqid); rtnl_unlock(); } EXPORT_SYMBOL(cfg80211_sched_scan_stopped); int cfg80211_stop_sched_scan_req(struct cfg80211_registered_device *rdev, struct cfg80211_sched_scan_request *req, bool driver_initiated) { ASSERT_RTNL(); if (!driver_initiated) { int err = rdev_sched_scan_stop(rdev, req->dev, req->reqid); if (err) return err; } nl80211_send_sched_scan(req, NL80211_CMD_SCHED_SCAN_STOPPED); cfg80211_del_sched_scan_req(rdev, req); return 0; } int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, u64 reqid, bool driver_initiated) { struct cfg80211_sched_scan_request *sched_scan_req; ASSERT_RTNL(); sched_scan_req = cfg80211_find_sched_scan_req(rdev, reqid); if (!sched_scan_req) return -ENOENT; return cfg80211_stop_sched_scan_req(rdev, sched_scan_req, driver_initiated); } void cfg80211_bss_age(struct cfg80211_registered_device *rdev, unsigned long age_secs) { struct cfg80211_internal_bss *bss; unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC); spin_lock_bh(&rdev->bss_lock); list_for_each_entry(bss, &rdev->bss_list, list) bss->ts -= age_jiffies; spin_unlock_bh(&rdev->bss_lock); } void cfg80211_bss_expire(struct cfg80211_registered_device *rdev) { __cfg80211_bss_expire(rdev, jiffies - IEEE80211_SCAN_RESULT_EXPIRE); } const u8 *cfg80211_find_ie_match(u8 eid, const u8 *ies, int len, const u8 *match, int match_len, int match_offset) { const struct element *elem; /* match_offset can't be smaller than 2, unless match_len is * zero, in which case match_offset must be zero as well. */ if (WARN_ON((match_len && match_offset < 2) || (!match_len && match_offset))) return NULL; for_each_element_id(elem, eid, ies, len) { if (elem->datalen >= match_offset - 2 + match_len && !memcmp(elem->data + match_offset - 2, match, match_len)) return (void *)elem; } return NULL; } EXPORT_SYMBOL(cfg80211_find_ie_match); const u8 *cfg80211_find_vendor_ie(unsigned int oui, int oui_type, const u8 *ies, int len) { const u8 *ie; u8 match[] = { oui >> 16, oui >> 8, oui, oui_type }; int match_len = (oui_type < 0) ? 3 : sizeof(match); if (WARN_ON(oui_type > 0xff)) return NULL; ie = cfg80211_find_ie_match(WLAN_EID_VENDOR_SPECIFIC, ies, len, match, match_len, 2); if (ie && (ie[1] < 4)) return NULL; return ie; } EXPORT_SYMBOL(cfg80211_find_vendor_ie); /** * enum bss_compare_mode - BSS compare mode * @BSS_CMP_REGULAR: regular compare mode (for insertion and normal find) * @BSS_CMP_HIDE_ZLEN: find hidden SSID with zero-length mode * @BSS_CMP_HIDE_NUL: find hidden SSID with NUL-ed out mode */ enum bss_compare_mode { BSS_CMP_REGULAR, BSS_CMP_HIDE_ZLEN, BSS_CMP_HIDE_NUL, }; static int cmp_bss(struct cfg80211_bss *a, struct cfg80211_bss *b, enum bss_compare_mode mode) { const struct cfg80211_bss_ies *a_ies, *b_ies; const u8 *ie1 = NULL; const u8 *ie2 = NULL; int i, r; if (a->channel != b->channel) return b->channel->center_freq - a->channel->center_freq; a_ies = rcu_access_pointer(a->ies); if (!a_ies) return -1; b_ies = rcu_access_pointer(b->ies); if (!b_ies) return 1; if (WLAN_CAPABILITY_IS_STA_BSS(a->capability)) ie1 = cfg80211_find_ie(WLAN_EID_MESH_ID, a_ies->data, a_ies->len); if (WLAN_CAPABILITY_IS_STA_BSS(b->capability)) ie2 = cfg80211_find_ie(WLAN_EID_MESH_ID, b_ies->data, b_ies->len); if (ie1 && ie2) { int mesh_id_cmp; if (ie1[1] == ie2[1]) mesh_id_cmp = memcmp(ie1 + 2, ie2 + 2, ie1[1]); else mesh_id_cmp = ie2[1] - ie1[1]; ie1 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, a_ies->data, a_ies->len); ie2 = cfg80211_find_ie(WLAN_EID_MESH_CONFIG, b_ies->data, b_ies->len); if (ie1 && ie2) { if (mesh_id_cmp) return mesh_id_cmp; if (ie1[1] != ie2[1]) return ie2[1] - ie1[1]; return memcmp(ie1 + 2, ie2 + 2, ie1[1]); } } r = memcmp(a->bssid, b->bssid, sizeof(a->bssid)); if (r) return r; ie1 = cfg80211_find_ie(WLAN_EID_SSID, a_ies->data, a_ies->len); ie2 = cfg80211_find_ie(WLAN_EID_SSID, b_ies->data, b_ies->len); if (!ie1 && !ie2) return 0; /* * Note that with "hide_ssid", the function returns a match if * the already-present BSS ("b") is a hidden SSID beacon for * the new BSS ("a"). */ /* sort missing IE before (left of) present IE */ if (!ie1) return -1; if (!ie2) return 1; switch (mode) { case BSS_CMP_HIDE_ZLEN: /* * In ZLEN mode we assume the BSS entry we're * looking for has a zero-length SSID. So if * the one we're looking at right now has that, * return 0. Otherwise, return the difference * in length, but since we're looking for the * 0-length it's really equivalent to returning * the length of the one we're looking at. * * No content comparison is needed as we assume * the content length is zero. */ return ie2[1]; case BSS_CMP_REGULAR: default: /* sort by length first, then by contents */ if (ie1[1] != ie2[1]) return ie2[1] - ie1[1]; return memcmp(ie1 + 2, ie2 + 2, ie1[1]); case BSS_CMP_HIDE_NUL: if (ie1[1] != ie2[1]) return ie2[1] - ie1[1]; /* this is equivalent to memcmp(zeroes, ie2 + 2, len) */ for (i = 0; i < ie2[1]; i++) if (ie2[i + 2]) return -1; return 0; } } static bool cfg80211_bss_type_match(u16 capability, enum nl80211_band band, enum ieee80211_bss_type bss_type) { bool ret = true; u16 mask, val; if (bss_type == IEEE80211_BSS_TYPE_ANY) return ret; if (band == NL80211_BAND_60GHZ) { mask = WLAN_CAPABILITY_DMG_TYPE_MASK; switch (bss_type) { case IEEE80211_BSS_TYPE_ESS: val = WLAN_CAPABILITY_DMG_TYPE_AP; break; case IEEE80211_BSS_TYPE_PBSS: val = WLAN_CAPABILITY_DMG_TYPE_PBSS; break; case IEEE80211_BSS_TYPE_IBSS: val = WLAN_CAPABILITY_DMG_TYPE_IBSS; break; default: return false; } } else { mask = WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS; switch (bss_type) { case IEEE80211_BSS_TYPE_ESS: val = WLAN_CAPABILITY_ESS; break; case IEEE80211_BSS_TYPE_IBSS: val = WLAN_CAPABILITY_IBSS; break; case IEEE80211_BSS_TYPE_MBSS: val = 0; break; default: return false; } } ret = ((capability & mask) == val); return ret; } /* Returned bss is reference counted and must be cleaned up appropriately. */ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, struct ieee80211_channel *channel, const u8 *bssid, const u8 *ssid, size_t ssid_len, enum ieee80211_bss_type bss_type, enum ieee80211_privacy privacy) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); struct cfg80211_internal_bss *bss, *res = NULL; unsigned long now = jiffies; int bss_privacy; trace_cfg80211_get_bss(wiphy, channel, bssid, ssid, ssid_len, bss_type, privacy); spin_lock_bh(&rdev->bss_lock); list_for_each_entry(bss, &rdev->bss_list, list) { if (!cfg80211_bss_type_match(bss->pub.capability, bss->pub.channel->band, bss_type)) continue; bss_privacy = (bss->pub.capability & WLAN_CAPABILITY_PRIVACY); if ((privacy == IEEE80211_PRIVACY_ON && !bss_privacy) || (privacy == IEEE80211_PRIVACY_OFF && bss_privacy)) continue; if (channel && bss->pub.channel != channel) continue; if (!is_valid_ether_addr(bss->pub.bssid)) continue; /* Don't get expired BSS structs */ if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) && !atomic_read(&bss->hold)) continue; if (is_bss(&bss->pub, bssid, ssid, ssid_len)) { res = bss; bss_ref_get(rdev, res); break; } } spin_unlock_bh(&rdev->bss_lock); if (!res) return NULL; trace_cfg80211_return_bss(&res->pub); return &res->pub; } EXPORT_SYMBOL(cfg80211_get_bss); static void rb_insert_bss(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *bss) { struct rb_node **p = &rdev->bss_tree.rb_node; struct rb_node *parent = NULL; struct cfg80211_internal_bss *tbss; int cmp; while (*p) { parent = *p; tbss = rb_entry(parent, struct cfg80211_internal_bss, rbn); cmp = cmp_bss(&bss->pub, &tbss->pub, BSS_CMP_REGULAR); if (WARN_ON(!cmp)) { /* will sort of leak this BSS */ return; } if (cmp < 0) p = &(*p)->rb_left; else p = &(*p)->rb_right; } rb_link_node(&bss->rbn, parent, p); rb_insert_color(&bss->rbn, &rdev->bss_tree); } static struct cfg80211_internal_bss * rb_find_bss(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *res, enum bss_compare_mode mode) { struct rb_node *n = rdev->bss_tree.rb_node; struct cfg80211_internal_bss *bss; int r; while (n) { bss = rb_entry(n, struct cfg80211_internal_bss, rbn); r = cmp_bss(&res->pub, &bss->pub, mode); if (r == 0) return bss; else if (r < 0) n = n->rb_left; else n = n->rb_right; } return NULL; } static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *new) { const struct cfg80211_bss_ies *ies; struct cfg80211_internal_bss *bss; const u8 *ie; int i, ssidlen; u8 fold = 0; u32 n_entries = 0; ies = rcu_access_pointer(new->pub.beacon_ies); if (WARN_ON(!ies)) return false; ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); if (!ie) { /* nothing to do */ return true; } ssidlen = ie[1]; for (i = 0; i < ssidlen; i++) fold |= ie[2 + i]; if (fold) { /* not a hidden SSID */ return true; } /* This is the bad part ... */ list_for_each_entry(bss, &rdev->bss_list, list) { /* * we're iterating all the entries anyway, so take the * opportunity to validate the list length accounting */ n_entries++; if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid)) continue; if (bss->pub.channel != new->pub.channel) continue; if (bss->pub.scan_width != new->pub.scan_width) continue; if (rcu_access_pointer(bss->pub.beacon_ies)) continue; ies = rcu_access_pointer(bss->pub.ies); if (!ies) continue; ie = cfg80211_find_ie(WLAN_EID_SSID, ies->data, ies->len); if (!ie) continue; if (ssidlen && ie[1] != ssidlen) continue; if (WARN_ON_ONCE(bss->pub.hidden_beacon_bss)) continue; if (WARN_ON_ONCE(!list_empty(&bss->hidden_list))) list_del(&bss->hidden_list); /* combine them */ list_add(&bss->hidden_list, &new->hidden_list); bss->pub.hidden_beacon_bss = &new->pub; new->refcount += bss->refcount; rcu_assign_pointer(bss->pub.beacon_ies, new->pub.beacon_ies); } WARN_ONCE(n_entries != rdev->bss_entries, "rdev bss entries[%d]/list[len:%d] corruption\n", rdev->bss_entries, n_entries); return true; } struct cfg80211_non_tx_bss { struct cfg80211_bss *tx_bss; u8 max_bssid_indicator; u8 bssid_index; }; /* Returned bss is reference counted and must be cleaned up appropriately. */ static struct cfg80211_internal_bss * cfg80211_bss_update(struct cfg80211_registered_device *rdev, struct cfg80211_internal_bss *tmp, bool signal_valid) { struct cfg80211_internal_bss *found = NULL; if (WARN_ON(!tmp->pub.channel)) return NULL; tmp->ts = jiffies; spin_lock_bh(&rdev->bss_lock); if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) { spin_unlock_bh(&rdev->bss_lock); return NULL; } found = rb_find_bss(rdev, tmp, BSS_CMP_REGULAR); if (found) { /* Update IEs */ if (rcu_access_pointer(tmp->pub.proberesp_ies)) { const struct cfg80211_bss_ies *old; old = rcu_access_pointer(found->pub.proberesp_ies); rcu_assign_pointer(found->pub.proberesp_ies, tmp->pub.proberesp_ies); /* Override possible earlier Beacon frame IEs */ rcu_assign_pointer(found->pub.ies, tmp->pub.proberesp_ies); if (old) kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); } else if (rcu_access_pointer(tmp->pub.beacon_ies)) { const struct cfg80211_bss_ies *old; struct cfg80211_internal_bss *bss; if (found->pub.hidden_beacon_bss && !list_empty(&found->hidden_list)) { const struct cfg80211_bss_ies *f; /* * The found BSS struct is one of the probe * response members of a group, but we're * receiving a beacon (beacon_ies in the tmp * bss is used). This can only mean that the * AP changed its beacon from not having an * SSID to showing it, which is confusing so * drop this information. */ f = rcu_access_pointer(tmp->pub.beacon_ies); kfree_rcu((struct cfg80211_bss_ies *)f, rcu_head); goto drop; } old = rcu_access_pointer(found->pub.beacon_ies); rcu_assign_pointer(found->pub.beacon_ies, tmp->pub.beacon_ies); /* Override IEs if they were from a beacon before */ if (old == rcu_access_pointer(found->pub.ies)) rcu_assign_pointer(found->pub.ies, tmp->pub.beacon_ies); /* Assign beacon IEs to all sub entries */ list_for_each_entry(bss, &found->hidden_list, hidden_list) { const struct cfg80211_bss_ies *ies; ies = rcu_access_pointer(bss->pub.beacon_ies); WARN_ON(ies != old); rcu_assign_pointer(bss->pub.beacon_ies, tmp->pub.beacon_ies); } if (old) kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); } found->pub.beacon_interval = tmp->pub.beacon_interval; /* * don't update the signal if beacon was heard on * adjacent channel. */ if (signal_valid) found->pub.signal = tmp->pub.signal; found->pub.capability = tmp->pub.capability; found->ts = tmp->ts; found->ts_boottime = tmp->ts_boottime; found->parent_tsf = tmp->parent_tsf; found->pub.chains = tmp->pub.chains; memcpy(found->pub.chain_signal, tmp->pub.chain_signal, IEEE80211_MAX_CHAINS); ether_addr_copy(found->parent_bssid, tmp->parent_bssid); found->pub.max_bssid_indicator = tmp->pub.max_bssid_indicator; found->pub.bssid_index = tmp->pub.bssid_index; } else { struct cfg80211_internal_bss *new; struct cfg80211_internal_bss *hidden; struct cfg80211_bss_ies *ies; /* * create a copy -- the "res" variable that is passed in * is allocated on the stack since it's not needed in the * more common case of an update */ new = kzalloc(sizeof(*new) + rdev->wiphy.bss_priv_size, GFP_ATOMIC); if (!new) { ies = (void *)rcu_dereference(tmp->pub.beacon_ies); if (ies) kfree_rcu(ies, rcu_head); ies = (void *)rcu_dereference(tmp->pub.proberesp_ies); if (ies) kfree_rcu(ies, rcu_head); goto drop; } memcpy(new, tmp, sizeof(*new)); new->refcount = 1; INIT_LIST_HEAD(&new->hidden_list); INIT_LIST_HEAD(&new->pub.nontrans_list); if (rcu_access_pointer(tmp->pub.proberesp_ies)) { hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN); if (!hidden) hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_NUL); if (hidden) { new->pub.hidden_beacon_bss = &hidden->pub; list_add(&new->hidden_list, &hidden->hidden_list); hidden->refcount++; rcu_assign_pointer(new->pub.beacon_ies, hidden->pub.beacon_ies); } } else { /* * Ok so we found a beacon, and don't have an entry. If * it's a beacon with hidden SSID, we might be in for an * expensive search for any probe responses that should * be grouped with this beacon for updates ... */ if (!cfg80211_combine_bsses(rdev, new)) { kfree(new); goto drop; } } if (rdev->bss_entries >= bss_entries_limit && !cfg80211_bss_expire_oldest(rdev)) { if (!list_empty(&new->hidden_list)) list_del(&new->hidden_list); kfree(new); goto drop; } /* This must be before the call to bss_ref_get */ if (tmp->pub.transmitted_bss) { struct cfg80211_internal_bss *pbss = container_of(tmp->pub.transmitted_bss, struct cfg80211_internal_bss, pub); new->pub.transmitted_bss = tmp->pub.transmitted_bss; bss_ref_get(rdev, pbss); } list_add_tail(&new->list, &rdev->bss_list); rdev->bss_entries++; rb_insert_bss(rdev, new); found = new; } rdev->bss_generation++; bss_ref_get(rdev, found); spin_unlock_bh(&rdev->bss_lock); return found; drop: spin_unlock_bh(&rdev->bss_lock); return NULL; } /* * Update RX channel information based on the available frame payload * information. This is mainly for the 2.4 GHz band where frames can be received * from neighboring channels and the Beacon frames use the DSSS Parameter Set * element to indicate the current (transmitting) channel, but this might also * be needed on other bands if RX frequency does not match with the actual * operating channel of a BSS. */ static struct ieee80211_channel * cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen, struct ieee80211_channel *channel, enum nl80211_bss_scan_width scan_width) { const u8 *tmp; u32 freq; int channel_number = -1; struct ieee80211_channel *alt_channel; tmp = cfg80211_find_ie(WLAN_EID_DS_PARAMS, ie, ielen); if (tmp && tmp[1] == 1) { channel_number = tmp[2]; } else { tmp = cfg80211_find_ie(WLAN_EID_HT_OPERATION, ie, ielen); if (tmp && tmp[1] >= sizeof(struct ieee80211_ht_operation)) { struct ieee80211_ht_operation *htop = (void *)(tmp + 2); channel_number = htop->primary_chan; } } if (channel_number < 0) { /* No channel information in frame payload */ return channel; } freq = ieee80211_channel_to_frequency(channel_number, channel->band); alt_channel = ieee80211_get_channel(wiphy, freq); if (!alt_channel) { if (channel->band == NL80211_BAND_2GHZ) { /* * Better not allow unexpected channels when that could * be going beyond the 1-11 range (e.g., discovering * BSS on channel 12 when radio is configured for * channel 11. */ return NULL; } /* No match for the payload channel number - ignore it */ return channel; } if (scan_width == NL80211_BSS_CHAN_WIDTH_10 || scan_width == NL80211_BSS_CHAN_WIDTH_5) { /* * Ignore channel number in 5 and 10 MHz channels where there * may not be an n:1 or 1:n mapping between frequencies and * channel numbers. */ return channel; } /* * Use the channel determined through the payload channel number * instead of the RX channel reported by the driver. */ if (alt_channel->flags & IEEE80211_CHAN_DISABLED) return NULL; return alt_channel; } /* Returned bss is reference counted and must be cleaned up appropriately. */ static struct cfg80211_bss * cfg80211_inform_single_bss_data(struct wiphy *wiphy, struct cfg80211_inform_bss *data, enum cfg80211_bss_frame_type ftype, const u8 *bssid, u64 tsf, u16 capability, u16 beacon_interval, const u8 *ie, size_t ielen, struct cfg80211_non_tx_bss *non_tx_data, gfp_t gfp) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); struct cfg80211_bss_ies *ies; struct ieee80211_channel *channel; struct cfg80211_internal_bss tmp = {}, *res; int bss_type; bool signal_valid; if (WARN_ON(!wiphy)) return NULL; if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && (data->signal < 0 || data->signal > 100))) return NULL; channel = cfg80211_get_bss_channel(wiphy, ie, ielen, data->chan, data->scan_width); if (!channel) return NULL; memcpy(tmp.pub.bssid, bssid, ETH_ALEN); tmp.pub.channel = channel; tmp.pub.scan_width = data->scan_width; tmp.pub.signal = data->signal; tmp.pub.beacon_interval = beacon_interval; tmp.pub.capability = capability; tmp.ts_boottime = data->boottime_ns; if (non_tx_data) { tmp.pub.transmitted_bss = non_tx_data->tx_bss; tmp.pub.bssid_index = non_tx_data->bssid_index; tmp.pub.max_bssid_indicator = non_tx_data->max_bssid_indicator; } /* * If we do not know here whether the IEs are from a Beacon or Probe * Response frame, we need to pick one of the options and only use it * with the driver that does not provide the full Beacon/Probe Response * frame. Use Beacon frame pointer to avoid indicating that this should * override the IEs pointer should we have received an earlier * indication of Probe Response data. */ ies = kzalloc(sizeof(*ies) + ielen, gfp); if (!ies) return NULL; ies->len = ielen; ies->tsf = tsf; ies->from_beacon = false; memcpy(ies->data, ie, ielen); switch (ftype) { case CFG80211_BSS_FTYPE_BEACON: ies->from_beacon = true; /* fall through to assign */ case CFG80211_BSS_FTYPE_UNKNOWN: rcu_assign_pointer(tmp.pub.beacon_ies, ies); break; case CFG80211_BSS_FTYPE_PRESP: rcu_assign_pointer(tmp.pub.proberesp_ies, ies); break; } rcu_assign_pointer(tmp.pub.ies, ies); signal_valid = abs(data->chan->center_freq - channel->center_freq) <= wiphy->max_adj_channel_rssi_comp; res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid); if (!res) return NULL; if (channel->band == NL80211_BAND_60GHZ) { bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) regulatory_hint_found_beacon(wiphy, channel, gfp); } else { if (res->pub.capability & WLAN_CAPABILITY_ESS) regulatory_hint_found_beacon(wiphy, channel, gfp); } if (non_tx_data && non_tx_data->tx_bss) { /* this is a nontransmitting bss, we need to add it to * transmitting bss' list if it is not there */ if (cfg80211_add_nontrans_list(non_tx_data->tx_bss, &res->pub)) { if (__cfg80211_unlink_bss(rdev, res)) rdev->bss_generation++; } } trace_cfg80211_return_bss(&res->pub); /* cfg80211_bss_update gives us a referenced result */ return &res->pub; } static void cfg80211_parse_mbssid_data(struct wiphy *wiphy, struct cfg80211_inform_bss *data, enum cfg80211_bss_frame_type ftype, const u8 *bssid, u64 tsf, u16 beacon_interval, const u8 *ie, size_t ielen, struct cfg80211_non_tx_bss *non_tx_data, gfp_t gfp) { const u8 *mbssid_index_ie; const struct element *elem, *sub; size_t new_ie_len; u8 new_bssid[ETH_ALEN]; u8 *new_ie; u16 capability; struct cfg80211_bss *bss; if (!non_tx_data) return; if (!cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen)) return; if (!wiphy->support_mbssid) return; if (wiphy->support_only_he_mbssid && !cfg80211_find_ext_ie(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen)) return; new_ie = kmalloc(IEEE80211_MAX_DATA_LEN, gfp); if (!new_ie) return; for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) { if (elem->datalen < 4) continue; for_each_element(sub, elem->data + 1, elem->datalen - 1) { if (sub->id != 0 || sub->datalen < 4) { /* not a valid BSS profile */ continue; } if (sub->data[0] != WLAN_EID_NON_TX_BSSID_CAP || sub->data[1] != 2) { /* The first element within the Nontransmitted * BSSID Profile is not the Nontransmitted * BSSID Capability element. */ continue; } /* found a Nontransmitted BSSID Profile */ mbssid_index_ie = cfg80211_find_ie (WLAN_EID_MULTI_BSSID_IDX, sub->data, sub->datalen); if (!mbssid_index_ie || mbssid_index_ie[1] < 1 || mbssid_index_ie[2] == 0) { /* No valid Multiple BSSID-Index element */ continue; } non_tx_data->bssid_index = mbssid_index_ie[2]; non_tx_data->max_bssid_indicator = elem->data[0]; cfg80211_gen_new_bssid(bssid, non_tx_data->max_bssid_indicator, non_tx_data->bssid_index, new_bssid); memset(new_ie, 0, IEEE80211_MAX_DATA_LEN); new_ie_len = cfg80211_gen_new_ie(ie, ielen, sub->data, sub->datalen, new_ie, gfp); if (!new_ie_len) continue; capability = get_unaligned_le16(sub->data + 2); bss = cfg80211_inform_single_bss_data(wiphy, data, ftype, new_bssid, tsf, capability, beacon_interval, new_ie, new_ie_len, non_tx_data, gfp); if (!bss) break; cfg80211_put_bss(wiphy, bss); } } kfree(new_ie); } struct cfg80211_bss * cfg80211_inform_bss_data(struct wiphy *wiphy, struct cfg80211_inform_bss *data, enum cfg80211_bss_frame_type ftype, const u8 *bssid, u64 tsf, u16 capability, u16 beacon_interval, const u8 *ie, size_t ielen, gfp_t gfp) { struct cfg80211_bss *res; struct cfg80211_non_tx_bss non_tx_data; res = cfg80211_inform_single_bss_data(wiphy, data, ftype, bssid, tsf, capability, beacon_interval, ie, ielen, NULL, gfp); non_tx_data.tx_bss = res; cfg80211_parse_mbssid_data(wiphy, data, ftype, bssid, tsf, beacon_interval, ie, ielen, &non_tx_data, gfp); return res; } EXPORT_SYMBOL(cfg80211_inform_bss_data); static void cfg80211_parse_mbssid_frame_data(struct wiphy *wiphy, struct cfg80211_inform_bss *data, struct ieee80211_mgmt *mgmt, size_t len, struct cfg80211_non_tx_bss *non_tx_data, gfp_t gfp) { enum cfg80211_bss_frame_type ftype; const u8 *ie = mgmt->u.probe_resp.variable; size_t ielen = len - offsetof(struct ieee80211_mgmt, u.probe_resp.variable); ftype = ieee80211_is_beacon(mgmt->frame_control) ? CFG80211_BSS_FTYPE_BEACON : CFG80211_BSS_FTYPE_PRESP; cfg80211_parse_mbssid_data(wiphy, data, ftype, mgmt->bssid, le64_to_cpu(mgmt->u.probe_resp.timestamp), le16_to_cpu(mgmt->u.probe_resp.beacon_int), ie, ielen, non_tx_data, gfp); } static void cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, struct cfg80211_bss *nontrans_bss, struct ieee80211_mgmt *mgmt, size_t len, gfp_t gfp) { u8 *ie, *new_ie, *pos; const u8 *nontrans_ssid, *trans_ssid, *mbssid; size_t ielen = len - offsetof(struct ieee80211_mgmt, u.probe_resp.variable); size_t new_ie_len; struct cfg80211_bss_ies *new_ies; const struct cfg80211_bss_ies *old; size_t cpy_len; ie = mgmt->u.probe_resp.variable; new_ie_len = ielen; trans_ssid = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen); if (!trans_ssid) return; new_ie_len -= trans_ssid[1]; mbssid = cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen); /* * It's not valid to have the MBSSID element before SSID * ignore if that happens - the code below assumes it is * after (while copying things inbetween). */ if (!mbssid || mbssid < trans_ssid) return; new_ie_len -= mbssid[1]; rcu_read_lock(); nontrans_ssid = ieee80211_bss_get_ie(nontrans_bss, WLAN_EID_SSID); if (!nontrans_ssid) { rcu_read_unlock(); return; } new_ie_len += nontrans_ssid[1]; rcu_read_unlock(); /* generate new ie for nontrans BSS * 1. replace SSID with nontrans BSS' SSID * 2. skip MBSSID IE */ new_ie = kzalloc(new_ie_len, gfp); if (!new_ie) return; new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, gfp); if (!new_ies) { kfree(new_ie); return; } pos = new_ie; /* copy the nontransmitted SSID */ cpy_len = nontrans_ssid[1] + 2; memcpy(pos, nontrans_ssid, cpy_len); pos += cpy_len; /* copy the IEs between SSID and MBSSID */ cpy_len = trans_ssid[1] + 2; memcpy(pos, (trans_ssid + cpy_len), (mbssid - (trans_ssid + cpy_len))); pos += (mbssid - (trans_ssid + cpy_len)); /* copy the IEs after MBSSID */ cpy_len = mbssid[1] + 2; memcpy(pos, mbssid + cpy_len, ((ie + ielen) - (mbssid + cpy_len))); /* update ie */ new_ies->len = new_ie_len; new_ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); new_ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control); memcpy(new_ies->data, new_ie, new_ie_len); if (ieee80211_is_probe_resp(mgmt->frame_control)) { old = rcu_access_pointer(nontrans_bss->proberesp_ies); rcu_assign_pointer(nontrans_bss->proberesp_ies, new_ies); rcu_assign_pointer(nontrans_bss->ies, new_ies); if (old) kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); } else { old = rcu_access_pointer(nontrans_bss->beacon_ies); rcu_assign_pointer(nontrans_bss->beacon_ies, new_ies); rcu_assign_pointer(nontrans_bss->ies, new_ies); if (old) kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head); } } /* cfg80211_inform_bss_width_frame helper */ static struct cfg80211_bss * cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, struct cfg80211_inform_bss *data, struct ieee80211_mgmt *mgmt, size_t len, struct cfg80211_non_tx_bss *non_tx_data, gfp_t gfp) { struct cfg80211_internal_bss tmp = {}, *res; struct cfg80211_bss_ies *ies; struct ieee80211_channel *channel; bool signal_valid; size_t ielen = len - offsetof(struct ieee80211_mgmt, u.probe_resp.variable); int bss_type; BUILD_BUG_ON(offsetof(struct ieee80211_mgmt, u.probe_resp.variable) != offsetof(struct ieee80211_mgmt, u.beacon.variable)); trace_cfg80211_inform_bss_frame(wiphy, data, mgmt, len); if (WARN_ON(!mgmt)) return NULL; if (WARN_ON(!wiphy)) return NULL; if (WARN_ON(wiphy->signal_type == CFG80211_SIGNAL_TYPE_UNSPEC && (data->signal < 0 || data->signal > 100))) return NULL; if (WARN_ON(len < offsetof(struct ieee80211_mgmt, u.probe_resp.variable))) return NULL; channel = cfg80211_get_bss_channel(wiphy, mgmt->u.beacon.variable, ielen, data->chan, data->scan_width); if (!channel) return NULL; ies = kzalloc(sizeof(*ies) + ielen, gfp); if (!ies) return NULL; ies->len = ielen; ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control); memcpy(ies->data, mgmt->u.probe_resp.variable, ielen); if (ieee80211_is_probe_resp(mgmt->frame_control)) rcu_assign_pointer(tmp.pub.proberesp_ies, ies); else rcu_assign_pointer(tmp.pub.beacon_ies, ies); rcu_assign_pointer(tmp.pub.ies, ies); memcpy(tmp.pub.bssid, mgmt->bssid, ETH_ALEN); tmp.pub.channel = channel; tmp.pub.scan_width = data->scan_width; tmp.pub.signal = data->signal; tmp.pub.beacon_interval = le16_to_cpu(mgmt->u.probe_resp.beacon_int); tmp.pub.capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); tmp.ts_boottime = data->boottime_ns; tmp.parent_tsf = data->parent_tsf; tmp.pub.chains = data->chains; memcpy(tmp.pub.chain_signal, data->chain_signal, IEEE80211_MAX_CHAINS); ether_addr_copy(tmp.parent_bssid, data->parent_bssid); if (non_tx_data) { tmp.pub.transmitted_bss = non_tx_data->tx_bss; tmp.pub.bssid_index = non_tx_data->bssid_index; tmp.pub.max_bssid_indicator = non_tx_data->max_bssid_indicator; } signal_valid = abs(data->chan->center_freq - channel->center_freq) <= wiphy->max_adj_channel_rssi_comp; res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid); if (!res) return NULL; if (channel->band == NL80211_BAND_60GHZ) { bss_type = res->pub.capability & WLAN_CAPABILITY_DMG_TYPE_MASK; if (bss_type == WLAN_CAPABILITY_DMG_TYPE_AP || bss_type == WLAN_CAPABILITY_DMG_TYPE_PBSS) regulatory_hint_found_beacon(wiphy, channel, gfp); } else { if (res->pub.capability & WLAN_CAPABILITY_ESS) regulatory_hint_found_beacon(wiphy, channel, gfp); } trace_cfg80211_return_bss(&res->pub); /* cfg80211_bss_update gives us a referenced result */ return &res->pub; } struct cfg80211_bss * cfg80211_inform_bss_frame_data(struct wiphy *wiphy, struct cfg80211_inform_bss *data, struct ieee80211_mgmt *mgmt, size_t len, gfp_t gfp) { struct cfg80211_bss *res, *tmp_bss; const u8 *ie = mgmt->u.probe_resp.variable; const struct cfg80211_bss_ies *ies1, *ies2; size_t ielen = len - offsetof(struct ieee80211_mgmt, u.probe_resp.variable); struct cfg80211_non_tx_bss non_tx_data; res = cfg80211_inform_single_bss_frame_data(wiphy, data, mgmt, len, NULL, gfp); if (!res || !wiphy->support_mbssid || !cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen)) return res; if (wiphy->support_only_he_mbssid && !cfg80211_find_ext_ie(WLAN_EID_EXT_HE_CAPABILITY, ie, ielen)) return res; non_tx_data.tx_bss = res; /* process each non-transmitting bss */ cfg80211_parse_mbssid_frame_data(wiphy, data, mgmt, len, &non_tx_data, gfp); /* check if the res has other nontransmitting bss which is not * in MBSSID IE */ ies1 = rcu_access_pointer(res->ies); /* go through nontrans_list, if the timestamp of the BSS is * earlier than the timestamp of the transmitting BSS then * update it */ list_for_each_entry(tmp_bss, &res->nontrans_list, nontrans_list) { ies2 = rcu_access_pointer(tmp_bss->ies); if (ies2->tsf < ies1->tsf) cfg80211_update_notlisted_nontrans(wiphy, tmp_bss, mgmt, len, gfp); } return res; } EXPORT_SYMBOL(cfg80211_inform_bss_frame_data); void cfg80211_ref_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); struct cfg80211_internal_bss *bss; if (!pub) return; bss = container_of(pub, struct cfg80211_internal_bss, pub); spin_lock_bh(&rdev->bss_lock); bss_ref_get(rdev, bss); spin_unlock_bh(&rdev->bss_lock); } EXPORT_SYMBOL(cfg80211_ref_bss); void cfg80211_put_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); struct cfg80211_internal_bss *bss; if (!pub) return; bss = container_of(pub, struct cfg80211_internal_bss, pub); spin_lock_bh(&rdev->bss_lock); bss_ref_put(rdev, bss); spin_unlock_bh(&rdev->bss_lock); } EXPORT_SYMBOL(cfg80211_put_bss); void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); struct cfg80211_internal_bss *bss, *tmp1; struct cfg80211_bss *nontrans_bss, *tmp; if (WARN_ON(!pub)) return; bss = container_of(pub, struct cfg80211_internal_bss, pub); spin_lock_bh(&rdev->bss_lock); if (list_empty(&bss->list)) goto out; list_for_each_entry_safe(nontrans_bss, tmp, &pub->nontrans_list, nontrans_list) { tmp1 = container_of(nontrans_bss, struct cfg80211_internal_bss, pub); if (__cfg80211_unlink_bss(rdev, tmp1)) rdev->bss_generation++; } if (__cfg80211_unlink_bss(rdev, bss)) rdev->bss_generation++; out: spin_unlock_bh(&rdev->bss_lock); } EXPORT_SYMBOL(cfg80211_unlink_bss); #ifdef CONFIG_CFG80211_WEXT static struct cfg80211_registered_device * cfg80211_get_dev_from_ifindex(struct net *net, int ifindex) { struct cfg80211_registered_device *rdev; struct net_device *dev; ASSERT_RTNL(); dev = dev_get_by_index(net, ifindex); if (!dev) return ERR_PTR(-ENODEV); if (dev->ieee80211_ptr) rdev = wiphy_to_rdev(dev->ieee80211_ptr->wiphy); else rdev = ERR_PTR(-ENODEV); dev_put(dev); return rdev; } int cfg80211_wext_siwscan(struct net_device *dev, struct iw_request_info *info, union iwreq_data *wrqu, char *extra) { struct cfg80211_registered_device *rdev; struct wiphy *wiphy; struct iw_scan_req *wreq = NULL; struct cfg80211_scan_request *creq = NULL; int i, err, n_channels = 0; enum nl80211_band band; if (!netif_running(dev)) return -ENETDOWN; if (wrqu->data.length == sizeof(struct iw_scan_req)) wreq = (struct iw_scan_req *)extra; rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); if (IS_ERR(rdev)) return PTR_ERR(rdev); if (rdev->scan_req || rdev->scan_msg) { err = -EBUSY; goto out; } wiphy = &rdev->wiphy; /* Determine number of channels, needed to allocate creq */ if (wreq && wreq->num_channels) n_channels = wreq->num_channels; else n_channels = ieee80211_get_num_supported_channels(wiphy); creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) + n_channels * sizeof(void *), GFP_ATOMIC); if (!creq) { err = -ENOMEM; goto out; } creq->wiphy = wiphy; creq->wdev = dev->ieee80211_ptr; /* SSIDs come after channels */ creq->ssids = (void *)&creq->channels[n_channels]; creq->n_channels = n_channels; creq->n_ssids = 1; creq->scan_start = jiffies; /* translate "Scan on frequencies" request */ i = 0; for (band = 0; band < NUM_NL80211_BANDS; band++) { int j; if (!wiphy->bands[band]) continue; for (j = 0; j < wiphy->bands[band]->n_channels; j++) { /* ignore disabled channels */ if (wiphy->bands[band]->channels[j].flags & IEEE80211_CHAN_DISABLED) continue; /* If we have a wireless request structure and the * wireless request specifies frequencies, then search * for the matching hardware channel. */ if (wreq && wreq->num_channels) { int k; int wiphy_freq = wiphy->bands[band]->channels[j].center_freq; for (k = 0; k < wreq->num_channels; k++) { struct iw_freq *freq = &wreq->channel_list[k]; int wext_freq = cfg80211_wext_freq(freq); if (wext_freq == wiphy_freq) goto wext_freq_found; } goto wext_freq_not_found; } wext_freq_found: creq->channels[i] = &wiphy->bands[band]->channels[j]; i++; wext_freq_not_found: ; } } /* No channels found? */ if (!i) { err = -EINVAL; goto out; } /* Set real number of channels specified in creq->channels[] */ creq->n_channels = i; /* translate "Scan for SSID" request */ if (wreq) { if (wrqu->data.flags & IW_SCAN_THIS_ESSID) { if (wreq->essid_len > IEEE80211_MAX_SSID_LEN) { err = -EINVAL; goto out; } memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len); creq->ssids[0].ssid_len = wreq->essid_len; } if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) creq->n_ssids = 0; } for (i = 0; i < NUM_NL80211_BANDS; i++) if (wiphy->bands[i]) creq->rates[i] = (1 << wiphy->bands[i]->n_bitrates) - 1; eth_broadcast_addr(creq->bssid); rdev->scan_req = creq; err = rdev_scan(rdev, creq); if (err) { rdev->scan_req = NULL; /* creq will be freed below */ } else { nl80211_send_scan_start(rdev, dev->ieee80211_ptr); /* creq now owned by driver */ creq = NULL; dev_hold(dev); } out: kfree(creq); return err; } EXPORT_WEXT_HANDLER(cfg80211_wext_siwscan); static char *ieee80211_scan_add_ies(struct iw_request_info *info, const struct cfg80211_bss_ies *ies, char *current_ev, char *end_buf) { const u8 *pos, *end, *next; struct iw_event iwe; if (!ies) return current_ev; /* * If needed, fragment the IEs buffer (at IE boundaries) into short * enough fragments to fit into IW_GENERIC_IE_MAX octet messages. */ pos = ies->data; end = pos + ies->len; while (end - pos > IW_GENERIC_IE_MAX) { next = pos + 2 + pos[1]; while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX) next = next + 2 + next[1]; memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVGENIE; iwe.u.data.length = next - pos; current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, (void *)pos); if (IS_ERR(current_ev)) return current_ev; pos = next; } if (end > pos) { memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVGENIE; iwe.u.data.length = end - pos; current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, (void *)pos); if (IS_ERR(current_ev)) return current_ev; } return current_ev; } static char * ieee80211_bss(struct wiphy *wiphy, struct iw_request_info *info, struct cfg80211_internal_bss *bss, char *current_ev, char *end_buf) { const struct cfg80211_bss_ies *ies; struct iw_event iwe; const u8 *ie; u8 buf[50]; u8 *cfg, *p, *tmp; int rem, i, sig; bool ismesh = false; memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWAP; iwe.u.ap_addr.sa_family = ARPHRD_ETHER; memcpy(iwe.u.ap_addr.sa_data, bss->pub.bssid, ETH_ALEN); current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, IW_EV_ADDR_LEN); if (IS_ERR(current_ev)) return current_ev; memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWFREQ; iwe.u.freq.m = ieee80211_frequency_to_channel(bss->pub.channel->center_freq); iwe.u.freq.e = 0; current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, IW_EV_FREQ_LEN); if (IS_ERR(current_ev)) return current_ev; memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWFREQ; iwe.u.freq.m = bss->pub.channel->center_freq; iwe.u.freq.e = 6; current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, IW_EV_FREQ_LEN); if (IS_ERR(current_ev)) return current_ev; if (wiphy->signal_type != CFG80211_SIGNAL_TYPE_NONE) { memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVQUAL; iwe.u.qual.updated = IW_QUAL_LEVEL_UPDATED | IW_QUAL_NOISE_INVALID | IW_QUAL_QUAL_UPDATED; switch (wiphy->signal_type) { case CFG80211_SIGNAL_TYPE_MBM: sig = bss->pub.signal / 100; iwe.u.qual.level = sig; iwe.u.qual.updated |= IW_QUAL_DBM; if (sig < -110) /* rather bad */ sig = -110; else if (sig > -40) /* perfect */ sig = -40; /* will give a range of 0 .. 70 */ iwe.u.qual.qual = sig + 110; break; case CFG80211_SIGNAL_TYPE_UNSPEC: iwe.u.qual.level = bss->pub.signal; /* will give range 0 .. 100 */ iwe.u.qual.qual = bss->pub.signal; break; default: /* not reached */ break; } current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, IW_EV_QUAL_LEN); if (IS_ERR(current_ev)) return current_ev; } memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWENCODE; if (bss->pub.capability & WLAN_CAPABILITY_PRIVACY) iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; else iwe.u.data.flags = IW_ENCODE_DISABLED; iwe.u.data.length = 0; current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, ""); if (IS_ERR(current_ev)) return current_ev; rcu_read_lock(); ies = rcu_dereference(bss->pub.ies); rem = ies->len; ie = ies->data; while (rem >= 2) { /* invalid data */ if (ie[1] > rem - 2) break; switch (ie[0]) { case WLAN_EID_SSID: memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWESSID; iwe.u.data.length = ie[1]; iwe.u.data.flags = 1; current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, (u8 *)ie + 2); if (IS_ERR(current_ev)) goto unlock; break; case WLAN_EID_MESH_ID: memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWESSID; iwe.u.data.length = ie[1]; iwe.u.data.flags = 1; current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, (u8 *)ie + 2); if (IS_ERR(current_ev)) goto unlock; break; case WLAN_EID_MESH_CONFIG: ismesh = true; if (ie[1] != sizeof(struct ieee80211_meshconf_ie)) break; cfg = (u8 *)ie + 2; memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVCUSTOM; sprintf(buf, "Mesh Network Path Selection Protocol ID: " "0x%02X", cfg[0]); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; sprintf(buf, "Path Selection Metric ID: 0x%02X", cfg[1]); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; sprintf(buf, "Congestion Control Mode ID: 0x%02X", cfg[2]); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; sprintf(buf, "Synchronization ID: 0x%02X", cfg[3]); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; sprintf(buf, "Authentication ID: 0x%02X", cfg[4]); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; sprintf(buf, "Formation Info: 0x%02X", cfg[5]); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; sprintf(buf, "Capabilities: 0x%02X", cfg[6]); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; break; case WLAN_EID_SUPP_RATES: case WLAN_EID_EXT_SUPP_RATES: /* display all supported rates in readable format */ p = current_ev + iwe_stream_lcp_len(info); memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWRATE; /* Those two flags are ignored... */ iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0; for (i = 0; i < ie[1]; i++) { iwe.u.bitrate.value = ((ie[i + 2] & 0x7f) * 500000); tmp = p; p = iwe_stream_add_value(info, current_ev, p, end_buf, &iwe, IW_EV_PARAM_LEN); if (p == tmp) { current_ev = ERR_PTR(-E2BIG); goto unlock; } } current_ev = p; break; } rem -= ie[1] + 2; ie += ie[1] + 2; } if (bss->pub.capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) || ismesh) { memset(&iwe, 0, sizeof(iwe)); iwe.cmd = SIOCGIWMODE; if (ismesh) iwe.u.mode = IW_MODE_MESH; else if (bss->pub.capability & WLAN_CAPABILITY_ESS) iwe.u.mode = IW_MODE_MASTER; else iwe.u.mode = IW_MODE_ADHOC; current_ev = iwe_stream_add_event_check(info, current_ev, end_buf, &iwe, IW_EV_UINT_LEN); if (IS_ERR(current_ev)) goto unlock; } memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVCUSTOM; sprintf(buf, "tsf=%016llx", (unsigned long long)(ies->tsf)); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; memset(&iwe, 0, sizeof(iwe)); iwe.cmd = IWEVCUSTOM; sprintf(buf, " Last beacon: %ums ago", elapsed_jiffies_msecs(bss->ts)); iwe.u.data.length = strlen(buf); current_ev = iwe_stream_add_point_check(info, current_ev, end_buf, &iwe, buf); if (IS_ERR(current_ev)) goto unlock; current_ev = ieee80211_scan_add_ies(info, ies, current_ev, end_buf); unlock: rcu_read_unlock(); return current_ev; } static int ieee80211_scan_results(struct cfg80211_registered_device *rdev, struct iw_request_info *info, char *buf, size_t len) { char *current_ev = buf; char *end_buf = buf + len; struct cfg80211_internal_bss *bss; int err = 0; spin_lock_bh(&rdev->bss_lock); cfg80211_bss_expire(rdev); list_for_each_entry(bss, &rdev->bss_list, list) { if (buf + len - current_ev <= IW_EV_ADDR_LEN) { err = -E2BIG; break; } current_ev = ieee80211_bss(&rdev->wiphy, info, bss, current_ev, end_buf); if (IS_ERR(current_ev)) { err = PTR_ERR(current_ev); break; } } spin_unlock_bh(&rdev->bss_lock); if (err) return err; return current_ev - buf; } int cfg80211_wext_giwscan(struct net_device *dev, struct iw_request_info *info, struct iw_point *data, char *extra) { struct cfg80211_registered_device *rdev; int res; if (!netif_running(dev)) return -ENETDOWN; rdev = cfg80211_get_dev_from_ifindex(dev_net(dev), dev->ifindex); if (IS_ERR(rdev)) return PTR_ERR(rdev); if (rdev->scan_req || rdev->scan_msg) return -EAGAIN; res = ieee80211_scan_results(rdev, info, extra, data->length); data->length = 0; if (res >= 0) { data->length = res; res = 0; } return res; } EXPORT_WEXT_HANDLER(cfg80211_wext_giwscan); #endif